<?php
declare (strict_types = 1);

namespace upload;

//文件上传
class Upload
{

    private $src;
    private $image;
    private $imageinfo;
    private $percent = 1;

     /**
      *
      * @param $src 源图
      * @param float $percent  压缩比例
      */
     public function __construct($src, $percent=1)
      {
          $this->src = $src;
          $this->percent = $percent;
      }


      /** 高清压缩图片
      * @param string $saveName  提供图片名（可不带扩展名，用源图扩展名）用于保存。或不提供文件名直接显示
      */
      public function compressImg($saveName='')
      {
          $this->_openImage();
          if(!empty($saveName)) $this->_saveImage($saveName);  //保存
          else $this->_showImage();
      }

      /**
      * 内部：打开图片
      */
      private function _openImage()
      {
          list($width, $height, $type, $attr) = getimagesize($this->src);
          $this->imageinfo = array(
                     'width'=>$width,
              'height'=>$height,
              'type'=>image_type_to_extension($type,false),
              'attr'=>$attr
          );
          $fun = "imagecreatefrom".$this->imageinfo['type'];
          $this->image = $fun($this->src);
          $this->_thumpImage();
      }
      /**
      * 内部：操作图片
      */
      private function _thumpImage()
      {
          $new_width = (int)round($this->imageinfo['width'] * $this->percent);
          $new_height = (int)round($this->imageinfo['height'] * $this->percent);
          $image_thump = imagecreatetruecolor($new_width,$new_height);

          /* --- 用以处理缩放gif和png图透明背景变黑色问题 开始 --- */
          $color = imagecolorallocate($image_thump,255,255,255);
          imagecolortransparent($image_thump,$color);
          imagefill($image_thump,0,0,$color);
          /* --- 用以处理缩放gif和png图透明背景变黑色问题 结束 --- */

          //将原图复制带图片载体上面，并且按照一定比例压缩,极大的保持了清晰度
          imagecopyresampled($image_thump,$this->image,0,0,0,0,$new_width,$new_height,$this->imageinfo['width'],$this->imageinfo['height']);
          imagedestroy($this->image);
          $this->image = $image_thump;
      }
      /**
      * 输出图片:保存图片则用saveImage()
      */
      private function _showImage()
      {
          header('Content-Type: image/'.$this->imageinfo['type']);
          $funcs = "image".$this->imageinfo['type'];
          $funcs($this->image);
      }

      /**
      * 保存图片到硬盘：
      * @param  string $dstImgName  1、可指定字符串不带后缀的名称，使用源图扩展名 。2、直接指定目标图片名带扩展名。
      */
      private function _saveImage($dstImgName)
      {
          if(empty($dstImgName)) return false;
          $allowImgs = ['.jpg', '.jpeg', '.png', '.bmp', '.wbmp','.gif'];   //如果目标图片名有后缀就用目标图片扩展名 后缀，如果没有，则用源图的扩展名
          $dstExt =  strrchr($dstImgName ,".");
          $sourseExt = strrchr($this->src ,".");
            if(!empty($dstExt)) $dstExt =strtolower($dstExt);
          if(!empty($sourseExt)) $sourseExt =strtolower($sourseExt);

          //有指定目标名扩展名
          if(!empty($dstExt) && in_array($dstExt,$allowImgs)){
                     $dstName = $dstImgName;
          }elseif(!empty($sourseExt) && in_array($sourseExt,$allowImgs)){
                     $dstName = $dstImgName.$sourseExt;
          }else{
                     $dstName = $dstImgName.$this->imageinfo['type'];
          }
         $funcs = "image".$this->imageinfo['type'];
          $funcs($this->image,$dstName);
     }
          /**
      * 销毁图片
      */
     public function __destruct(){
         imagedestroy($this->image);
     }

     /**
      * 删除图片
      */





}
